Sensor-equipped display device and sensor device

ABSTRACT

According to one embodiment, a sensor-equipped display device includes first electrodes and a detection electrode. The first electrodes constitute sensor drive electrodes by being supplied with sensor drive signals separately and sequentially or sensor drive electrodes by simultaneously supplying the sensor drive signals to the first electrodes adjacent to each other. A width of the sensor drive electrode including the first electrode on the edge is smaller than a width of the other sensor drive electrode not including the first electrode on the edge.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of application Ser. No. 16/444,377filed Jun. 18, 2019, which is a Continuation of application Ser. No.16/121,169 filed Sep. 4, 2018, now U.S. Pat. No. 10,379,652 issued onAug. 13, 2019, which is a Continuation of application Ser. No.15/424,079, filed Feb. 3, 2017, now U.S. Pat. No. 10,095,338 issued onOct. 9, 2018, which is based upon and claims the benefit of priorityfrom Japanese Patent Application No. 2016-018948, filed Feb. 3, 2016,the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a sensor-equippeddisplay device and a sensor device.

BACKGROUND

As an example of sensor-equipped display devices, a capacitive sensorcapable of detecting contact or approach of an object, based on a changein the electrostatic capacitance, has been recently developed. Detectionelectrodes and sensor drive electrodes constituting such a sensor aredisposed in a display area where an image is displayed, and opposed toeach other with dielectrics interposed between the electrodes. Thedetection electrodes are electrically connected to lead lines locatedoutside the display area.

Demands for downsizing of the display device are increased while thedisplay area is extended, and the periphery outside the display areatends to become a narrow frame. For this reason, sensor drive electrodesare often disposed closely to lead lines. In this case, the lead linesare considered to function as sensors by capacitive coupling between thesensor drive electrodes and the lead lines.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a configuration of asensor-equipped liquid crystal display device of a first embodiment.

FIG. 2 is an illustration showing an equivalent circuit and a basicconfiguration of the liquid crystal display device shown in FIG. 1.

FIG. 3 is an equivalent circuit diagram of a pixel shown in FIG. 2.

FIG. 4 is a cross-sectional view schematically showing a structure ofthe liquid crystal display device in part.

FIG. 5 is a plan view showing a configuration of a sensor of the firstembodiment.

FIG. 6 is an enlarged plan view showing the sensor in part.

FIG. 7 is another enlarged plan view showing the sensor in part.

FIG. 8 is a line graph representing a value of capacitance between asensor drive electrode and a detection electrode, in each sensor driveelectrode of the first embodiment.

FIG. 9 is a cross-sectional view showing a structure of a display panelincluding the sensor in part.

FIG. 10 is an illustration for explanation of a principle of a sensingmethod.

FIG. 11 is an enlarged plan view showing the sensor in part of thesensor-equipped liquid crystal display device of a comparative exampleof the first embodiment.

FIG. 12 is a line graph representing a value of capacitance between asensor drive electrode and a detection electrode, in each sensor driveelectrode of the comparative example.

FIG. 13 is an enlarged plan view showing a sensor in part of asensor-equipped liquid crystal display device of a second embodiment.

FIG. 14 is a table showing a relationship between a first electrode anda sensor drive electrode, of the second embodiment.

FIG. 15 is a timing chart for explanation of a method of driving thesensor-equipped liquid crystal display device of the second embodiment,illustrating a video signal, a common drive signal, and a write signal,in a first period of an F-th frame period.

FIG. 16 is a plan view showing a sensor in part, for explanation of anexample of the method of driving the sensor of the second embodiment.

FIG. 17 is a plan view showing a sensor in part, for explanation of anexample of the method of driving the sensor of the second embodiment,subsequently with FIG. 16.

FIG. 18 is a plan view showing a sensor in part, for explanation of anexample of the method of driving the sensor of the second embodiment,subsequently with FIG. 17.

FIG. 19 is a plan view showing a sensor in part, for explanation of anexample of the method of driving the sensor of the second embodiment,subsequently with FIG. 18.

FIG. 20 is a plan view showing a configuration of a sensor of asensor-equipped liquid crystal display device of a third embodiment.

FIG. 21 is a plan view showing a configuration of a sensor of asensor-equipped liquid crystal display device of a fourth embodiment.

FIG. 22 is a line graph representing a value of capacitance between asensor drive electrode and a detection electrode, in each sensor driveelectrode of the fourth embodiment.

FIG. 23 is a plan view showing a configuration of a sensor of asensor-equipped liquid crystal display device of a fifth embodiment.

FIG. 24 is a table showing a relationship among a first electrode, asecond electrode and a sensor drive electrode, of the fifth embodiment.

FIG. 25 is a plan view showing the configuration of the sensor-equippedliquid crystal display device of modified example 1 of the firstembodiment.

FIG. 26 is a perspective view showing the configuration of thesensor-equipped liquid crystal display device of modified example 2 ofthe first embodiment.

DETAILED DESCRIPTION

In general, according to one embodiment, there is provided asensor-equipped display device, comprising: first electrodes disposed ina display area, arranged in a first direction and spaced apart from eachother, and elongating in a second direction intersecting the firstdirection; and a detection electrode comprising a body portion opposedto the first electrodes, and an expanded portion which is opposed to thefirst electrode located on an outermost side, the expanded portionconnected to the body portion and being wider than the body portion, thefirst electrodes constituting sensor drive electrodes by being suppliedwith sensor drive signals separately and sequentially or sensor driveelectrodes by simultaneously supplying the sensor drive signals to thefirst electrodes adjacent to each other, a width of the sensor driveelectrode including the first electrode on the edge being smaller than awidth of the other sensor drive electrode not including the firstelectrode on the edge.

According to another embodiment, there is provided a sensor-equippeddisplay device, comprising: first electrodes disposed in a display area,arranged in a first direction and spaced apart from each other, andelongating in a second direction intersecting the first direction; asecond electrode disposed on an edge portion of the display area,elongating in the second direction, and being adjacent to and spacedapart from the first electrodes on edges located on outermost sides; adetection electrode comprising a body portion opposed to the firstelectrodes, and an expanded portion which is opposed to the secondelectrode, the detection electrode connected to the body portion andbeing wider than the body portion; and a controller urging the firstelectrodes to function as sensor drive electrodes by supplying sensordrive signals to the first electrodes separately and sequentially, orurging the first electrodes bundled adjacent to each other to functionas sensor drive electrodes by simultaneously supplying sensor drivesignals to the adjacent first electrodes, and maintaining an electricpotential of the second electrode at a value different from electricpotentials of the sensor drive electrodes in a sensing period forperforming sensing using the detection electrode.

According to yet another embodiment, there is provided a sensor device,comprising: first electrodes arranged in a first direction and spacedapart from each other, and elongating in a second direction intersectingthe first direction; and a detection electrode comprising a body portionopposed to the first electrodes, and an expanded portion which isopposed to the first electrode on an edge located on an outermost side,which is connected to the body portion, and which is wider than the bodyportion, the first electrodes constituting sensor drive electrodes bybeing supplied with sensor drive signals separately and sequentially orsensor drive electrodes formed of bundled first electrodes adjacent toeach other being constituted by simultaneously supplying the sensordrive signals to the first electrodes adjacent to each other, in thesensor drive electrodes constituted in accordance with supply of thesensor drive signals, a width of the sensor drive electrode includingthe first electrode on the edge being smaller than a width of the othersensor drive electrode not including the first electrode on the edge.

According to yet another embodiment, there is provided a sensor device,comprising: first electrodes arranged in a first direction and spacedapart from each other, and elongating in a second direction intersectingthe first direction; a second electrode disposed outside the firstelectrodes, elongating in the second direction, and being adjacent toand spaced apart from the first electrodes on edges located on outermostsides, of the first electrodes, in the first direction; a detectionelectrode comprising a body portion opposed to the first electrodes, andan expanded portion which is opposed to the second electrode, which isconnected to the body portion and which is wider than the body portion;and a controller urging the first electrodes to function as sensor driveelectrodes by supplying sensor drive signals to the first electrodesseparately and sequentially, or urging the bundled first electrodesadjacent to each other to function as sensor drive electrodes bysimultaneously supplying sensor drive signals to the adjacent firstelectrodes, and maintaining an electric potential of the secondelectrode at a value different from electric potentials of the sensordrive electrodes in a sensing period for performing sensing using thedetection electrode.

Embodiments will be described hereinafter with reference to theaccompanying drawings. The disclosure is a mere example, and properchanges in keeping with the spirit of the invention, which are easilyconceivable by a person of ordinary skill in the art, come within thescope of the invention as a matter of course. In addition, in somecases, in order to make the description clearer, the widths,thicknesses, shapes and the like of the respective parts are illustratedin the drawings schematically, rather than as an accurate representationof what is implemented, but such schematic illustration is merelyexemplary and in no way restricts the interpretation of the invention.In the present specification and drawings, elements like or similar tothose described in connection with preceding drawings may be denoted bylike or similar reference numbers and their detailed descriptions may beomitted unless necessary.

First, a basic concept of the embodiments will be described.

Sensor-equipped display devices are configured to detect data input on adisplay surface by input means. The sensor is a capacitive sensor, whichcomprises a sensor drive electrode, a detection electrode disposed to beopposed to the sensor drive electrode, and a lead line connected to thedetection electrode. A detected object such as a finger of a human and astylus can be used as an input means.

Demands for making a frame region (non-display area) around the displayarea narrower in the display device are increased. Thus, a size of theframe region tends to be reduced in the display device. Thus, lead linesin the frame region are considered to be disposed closely to a sensordrive electrode.

When the sensor drive electrode and the lead lines are close to eachother, a capacitive coupling (parasitic capacitance) is generatedbetween the sensor drive electrode and the lead lines. As the sensordrive electrode and lead lines are disposed more closely, the parasiticcapacitance becomes greater. For example, when a conductive materialcontacts or approaches the input surface of the display device in theproximity of the outermost periphery of the display area, the parasiticcapacitance between the sensor drive electrode and the lead lines isvaried and noise is caused to occur in the lead lines. In other words,not only a read signal indicative of a variation in the electrostaticcapacitance (strength degree of the electrostatic capacitive coupling)of the detection electrodes, which should be transferred as a detectionsignal, but a noise signal generated in the lead lines by the parasiticcapacitance, are transmitted to the lead lines. As the noise signal isgreater, an amplitude ratio (S/N ratio) of these signals is consequentlydegraded.

Each of the detection electrodes therefore comprises a body portionopposed to the sensor drive electrode, and an expanded portion expandedportion which is opposed to the sensor drive electrode and is wider thanthe body portion.

At least a part of the expanded portion is disposed on a peripheralportion of the display area. The expanded portion can urge capacitanceto be hardly formed between the sensor drive electrode and the leadlines through a gap in the body portion. Noise can be hardly generatedin the lead lines and the degradation of the S/N ratio can besuppressed. Furthermore, arrangement of at least a part of the expandedportion in the display area can contribute to reduction in area of theframe region.

However, the expanded portion is overlaid on the sensor drive electrodelocated in the display area, in planar view. In the regions where thesensor drive electrode and the detection electrode are opposed, area ofan overlaid portion of both the electrodes in the region where both thebody portion and the expanded portion are opposed to the sensor driveelectrode is larger than that in the region where the body portion aloneis opposed to the sensor drive electrode. As a result, a capacitance ofthe region including the expanded portion becomes large. For thisreason, keeping the capacitance between the sensor drive electrode andthe detection electrode constant over the entire display area isdifficult.

If the capacitance between the sensor drive electrode and the detectionelectrode is varied in a case where the conductive material contacts orapproaches the input surface of the display device, as explained above,the variation amount of the capacitance generated at the detectionelectrode is varied in accordance with the location though the sameconductive material is used. As a result, the detection accuracy may bevaried in accordance with the location.

In the embodiments, the sensor-equipped display device and the sensordevice capable of detecting input position information accurately can beprovided by solving the problem. Alternatively, the sensor-equippeddisplay device and the sensor device capable of suppressing thedetection errors of the sensor can be obtained. Next, means and mannersfor solving the problem will be explained.

First Embodiment

First, a sensor-equipped display device of the first embodiment will beexplained. The display device can be used for, for example, variousdevices such as a smartphone, a tablet terminal, a mobile telephoneterminal, a personal computer, a TV receiver, a vehicle-mounted device,and a game console. In the present embodiment, a liquid crystal displaydevice is described as an example of the sensor-equipped display device.FIG. 1 is a perspective view showing a configuration of thesensor-equipped liquid crystal display device of the present embodiment.

The major configuration explained in the present embodiment can also beapplied to a self-luminous display device comprising an organicelectroluminescent display element, and the like, an electronic paperdisplay device comprising a cataphoretic element, and the like, adisplay device employing micro-electro-mechanical systems (MEMS), or adisplay device employing electrochromism.

As shown in FIG. 1, a liquid crystal display device DSP comprises anactive-matrix display panel PNL, a driver IC chip IC1 which drives thedisplay panel PNL, a capacitive sensor SE, a driver IC chip IC2 whichdrives the sensor SE, a backlight unit BL which illuminates the displaypanel PNL, a control module CM, flexible printed circuits FPC1, FPC2 andFPC3, and the like. In the present embodiment, the display panel PNL isa liquid crystal display panel.

The display panel PNL includes a first substrate SUB1 in a plate shape,a second substrate SUB2 in a plate shape which is opposed to the firstsubstrate SUB1, and a liquid crystal layer (a liquid crystal layer LQexplained later) held between the first substrate SUB1 and the secondsubstrate SUB2. The display panel PNL includes a display area DA inwhich an image is displayed. In the example illustrated, the displaypanel PNL is a transmissive display panel having a transmissive displayfunction of displaying an image by urging light from the backlight unitBL to be transmitted selectively. The display panel PNL may be areflective display panel having a reflective display function ofdisplaying an image by urging external light and auxiliary lightincident from the second substrate SUB2 side to be reflectedselectively. In addition, the display panel PNL may be a transreflectivedisplay panel having the transmissive display function and thereflective display function.

The sensor SE comprises detection electrodes Rx. The detectionelectrodes Rx are disposed on, for example, the display surface of thedisplay panel PNL, i.e., the outer surface of the second substrate SUB2.The detection electrodes Rx are illustrated schematically. In theexample illustrated, the detection electrodes Rx extend substantially ina first direction X and are arranged in a second direction Y. Thedetection electrodes Rx may extend in the second direction Y and may bearranged in the first direction X. The first direction X and the seconddirection Y are orthogonal to each other. The first direction X and thesecond direction Y may intersect each other at an angle other than 90°.A third direction Z is orthogonal to each of the first direction X andthe second direction Y.

The driver IC chip IC1 is mounted on the first substrate SUB1 of thedisplay panel PNL. The flexible printed circuit FPC1 connects thedisplay panel PNL with the control module CM. The flexible printedcircuit FPC2 connects the detection electrodes Rx of the sensor SE withthe control module CM. The driver IC chip IC2 is mounted on the flexibleprinted circuit FPC2. The driver IC chip IC2 may be mounted on the firstsubstrate SUB1 or the control module CM. The flexible printed circuitFPC3 connects the backlight unit BL with the control module CM.

The driver IC chip IC1 and the driver IC chip IC2 are connected to eachother via the flexible printed circuit FPC2 and the like. For example,if the flexible printed circuit FPC2 includes a branch portion FPCBconnected to the first substrate SUB1, the driver IC chip IC1 and thedriver IC chip IC2 may be connected to each other via lines included inthe branch portion FPCB and lines on the first substrate SUB1. Inaddition, the driver IC chip IC1 and the driver IC chip IC2 may beconnected to each other via lines included in each of the flexibleprinted circuit FPC1 and the flexible printed circuit FPC2. Either ofthe driver IC chip IC1 and the driver IC chip IC2 can generate a timingsignal to notify a driving period of the sensor SE and supply the timingsignal to the other driver IC chip. Either of the driver IC chips IC1and IC2 can generate a timing signal to notify a driving period of acommon electrode CE which will be explained later, and supply the timingsignal to the other driver IC chip. Alternatively, the control module CMcan supply the timing signals to the driver IC chip IC1 and the driverIC chip IC2. The timing signals can be used to synchronize the drive ofthe driver IC chip IC1 and the drive of the driver IC chip IC2.

FIG. 2 is a view showing the equivalent circuit and the basicconfiguration of the liquid crystal display device DSP shown in FIG. 1.

As shown in FIG. 2, the liquid crystal display device DSP comprises asource line driver SD, a gate line driver GD, a common electrode driverCD and the like, in a non-display area NDA outside the display area DA,besides the display panel PNL and the like. For example, at least thesource line driver SD and the common electrode driver CD are partiallybuilt in the driver IC chip IC1. The non-display area NDA has a frameshape surrounding the display area DA.

The display panel PNL includes pixels PX in the display area DA. Thepixels PX are disposed in an m×n matrix in the first direction X and thesecond direction Y where m and n are positive integers. The pixels PXarranged in the first direction X form pixel rows and the pixels PXarranged in the second direction Y form pixel columns. The display panelPNL also includes n gate lines G (G1 to Gn), m source lines S (S1 toSm), a common electrode CE and the like in the display area DA.

The gate lines G extend in the first direction X to be drawn to theoutside of the display area DA and are connected to the gate line driverGD. The gate lines G are arranged in the second direction Y to be spacedapart from each other. The source lines S extend in the second directionY to be drawn to the outside of the display area DA and are connected tothe source line driver SD. The source lines S are arranged in the firstdirection X to be spaced apart from each other, and intersect the gatelines G. The gate lines G and the source lines S may not necessarilyextend linearly and may be partially bent. The common electrode CE isconnected to the common electrode driver CD. The common electrode CE isshared by the pixels PX. Details of the common electrode CE will bedescribed later.

FIG. 3 is an equivalent circuit diagram showing one of the pixels PXshown in FIG. 2.

As shown in FIG. 3, each pixel PX comprises a switching element PSW, apixel electrode PE, the common electrode CE, a liquid crystal layer LC,and the like. The switching element PSW is composed of, for example, athin thin-film transistor. The switching element PSW is electricallyconnected to the gate line G and the source line S. The switchingelement PSW may be in a top gate type or a bottom gate type. Asemiconductor layer of the switching element PSW is formed of, forexample, polycrystalline silicon but may be formed of amorphous silicon,an oxide semiconductor or the like. The pixel electrode PE iselectrically connected to the switching element PSW. The pixel electrodePE is opposed to the common electrode CE. A storage capacitor CS isformed, for example, between the common electrode CE and the pixelelectrode PE.

FIG. 4 is a cross-sectional view showing a part of the structure of theliquid crystal display device DSP.

As shown in FIG. 4, in the present embodiment, the display panel PNL maybe configured to correspond to any one of a display mode using alongitudinal electric field along a normal line of a main surface of thesubstrate, a display mode using an oblique electric field angled withrespect to the normal line of the main surface of the substrate, and adisplay mode using a lateral electric field along the main surface ofthe substrate. In addition, the display panel PNL may be configured tocorrespond to a display mode using an arbitrary combination of thelongitudinal, lateral, and oblique electric fields. The main surface ofthe substrate indicates a surface parallel to an X-Y plane defined bythe first direction X and the second direction Y that are orthogonal toeach other. In the display mode using the longitudinal electric field orthe oblique electric field, for example, the pixel electrodes PE aredisposed on the first substrate SUB1 while the common electrode CE isdisposed on the second substrate SUB2. In the display mode using thelateral electric field, the pixel electrodes PE and the common electrodeCE are disposed on the first substrate SUB1.

In the example illustrated, the display panel PNL is configured tocorrespond to the display mode using the lateral electric field. Asecond substrate SUB2 is opposed to the first substrate SUB1 and spacedapart from the first substrate SUB1 with a predetermined gap, on thedisplay panel PNL. The liquid crystal layer LC is located in the gapbetween the first substrate SUB1 and the second substrate SUB2.

The first substrate SUB1 includes a first insulating substrate 10 havinga light transmitting property of a glass substrate or a resin substrate.The first substrate SUB1 includes the gate lines, the switchingelements, the source lines S, the common electrode CE, the pixelelectrodes PE, a first insulating film 11, a second insulating film 12,a third insulating film 13, a first alignment film AL1 and the like, onan upper side of the first insulating substrate 10, i.e., the sideopposed to the second substrate SUB2.

Each pixel electrode PE is located between adjacent source lines S andopposed to the common electrode CE via the insulating film. In addition,each pixel electrode PE includes a slit SL at a position opposed to thecommon electrode CE. The common electrode CE and the pixel electrodes PEare formed of, for example, a transparent, electrically conductivematerial such as ITO or IZO. The first alignment film AL1 is formed onthe pixel electrodes PE and the third insulating film 13 to cover thepixel electrodes PE and the third insulating film 13.

The common electrode CE is thus located in a layer different from thelayer of the gate lines G and the source lines S, or the pixelelectrodes PE. For this reason, the common electrode CE can be disposedin a positional relationship of intersecting the gate lines G and thesource lines S, or the pixel electrodes PE in the X-Y plane, in planarview. In other words, the common electrode CE can be disposed across theadjacent pixels PX. In the present embodiment, the common electrode CEis formed in a strip shape, extends in the second direction Y, and has awidth which enables the common electrode to be opposed to the pixelcolumns.

The second substrate SUB2 includes a second insulating substrate 20having a light transmitting property of a glass substrate or a resinsubstrate. The second substrate SUB2 includes a light-shielding layerBM, color filters CFR, CFG and CFB corresponding to red, green and bluecolors, an overcoat layer OC, a second alignment film AL2 and the like,on a lower side of the second insulating substrate 20, i.e., the sideopposed to the first substrate SUB1. The light-shielding layer BM islocated on an inner surface of the second insulating substrate 20 topartition the pixels. Each of the color filters CFR, CFG, and CFB islocated on the inner surface of the second insulating substrate 20 andpartially overlaid on the light-shielding layer BM.

In the example illustrated, a unit pixel, which is the minimum unit of acolor image, is composed of three color pixels, i.e., the red pixel, thegreen pixel, and the blue pixel. However, the unit pixel is not limitedto a combination of three color pixels as explained above. For example,the unit pixel may be composed of four color pixels, i.e., the redpixel, the green pixel, the blue pixel and a white pixel. In this case,a white or transparent color filter may be disposed on the white pixelor the color filter of the white pixel may be omitted. The overcoatlayer OC covers the color filters CFR, CFG, and CFB. The overcoat layerOC is formed of a transparent resin material. The second alignment filmAL2 covers the overcoat layer OC.

The liquid crystal layer LC functions as a display function layer ofoperating in accordance with electric fields generated between thecommon electrode CE and the pixel electrodes PE. The common electrodeCE, the pixel electrodes PE, the liquid crystal layer LC and the likeare located between a pair of substrates, i.e., the first insulatingsubstrate 10 and the second insulating substrate 20.

The detection electrodes Rx are located on the outer surface ES side ofthe second insulating substrate 20. In the example illustrated, thedetection electrodes Rx are in contact with the outer surface ES of thesecond insulating substrate 20, but an insulating member may beinterposed between the detection electrodes Rx and the outer surface ES.

Details of the structure of the detection electrodes Rx will beexplained later. The illustration is simplified, and lead lines L andthe like which will be explained later are not illustrated. Thedetection electrodes Rx are formed of, for example, a metal materialsuch as aluminum, which will be explained later. The time required fordetection can be reduced by lowering the electric resistance value ofthe detection electrodes Rx. For this reason, use of metal detectionelectrodes Rx is beneficial for achievement of a larger size and ahigher fineness of the display panel PNL.

The detection electrodes Rx may also be formed of a combination(assembly) of a transparent conductive material (for example, astrip-shaped conductive layer) such as ITO or IZO, and a metal material(for example, a fine metal line). Each detection electrode Rx is opposedto the common electrode CE via dielectric members such as the thirdinsulating film 13, the first alignment film AL1, the liquid crystallayer LC, the second alignment film AL2, the overcoat layer OC, thecolor filters CFR, CFG and CFB, and the second insulating substrate 20.

The first optical element OD1 is interposed between the first insulatingsubstrate 10 and the backlight unit BL. The second optical element OD2is disposed above the detection electrode Rx. Each of the first opticalelement OD1 and the second optical element OD2 includes at least apolarizer and may include a retardation film as needed. The polarizersincluded in the first optical element OD1 and the second optical elementOD2 are disposed to have a crossed-Nicol relationship in whichabsorption axes of the respective polarizers intersect each other.

The second optical element comprises a conductive layer opposed to thedetection electrodes to cover the display area.

Next, a sensor SE mounted on the liquid crystal display device DSP ofthe present embodiment will be explained. FIG. 5 is a plan view showinga configuration of the sensor SE of the present embodiment.

As shown in FIG. 5, in the present embodiment, the sensor SE comprisesthe common electrode CE of the first substrate SUB1 and the detectionelectrodes Rx of the second substrate SUB2. In other words, the commonelectrode CE functions as an electrode for display by generating anelectric field between the common electrode CE and the pixel electrodesPE. The common electrode CE also functions as a sensor drive electrodeby generating capacitance between the common electrode CE and thedetection electrodes Rx.

The common electrode CE is disposed in the display area DA. In theexample illustrated, the common electrode CE includes first electrodesCa. The first electrodes Ca are arranged in the first direction X to bespaced apart from each other, in the display area DA. Each of the firstelectrodes Ca has a strip shape and elongates in the second direction Y.

The first electrodes Ca constitute sensor drive electrodes Tx by beingsupplied with sensor drive signals from a controller, sequentially andindependently. The sensor SE comprises the sensor drive electrodes Txand the detection electrodes Rx. In the present embodiment, the sensordrive electrodes Tx are h sensor drive electrodes Tx1, Tx2, . . . Txhincluding a first sensor drive electrode Tx1 to h-th sensor driveelectrode Txh.

The common electrode CE includes k first electrodes Ca (Ca1, Ca2, . . .Cak). Each of h and k indicates a natural number greater than or equalto two. In the present embodiment, each sensor drive electrode Tx iscomposed of a corresponding first electrode Ca (h=k).

Each detection electrode Rx comprises an expanded portion RSL and a bodyportion RR. The expanded portions RSL are arranged in the seconddirection Y. At least a part of the expanded portion RSL is disposed inthe display area DA.

In the present embodiment, the entire bodies of the expanded portionsRSL are disposed in the display area DA. The detection electrode Rxcomprises two expanded portions RSL, and the body portion RR issandwiched between two expanded portions RSL in the first direction X.The body portions RR are disposed in the display area DA and arranged inthe second direction Y. Each of the body portions RR elongates in astrip shape, in the first direction X. In other words, the body portionRR elongates in a direction intersecting the first electrodes Ca. Thebody portion RR is macroscopically formed in a strip shape asillustrated but, microscopically, the body portion RR is composed of anassembly of fine metal lines as explained later. In addition, theexpanded portion RSL is macroscopically formed in a square shape asillustrated but, microscopically, the expanded portion RSL is composedof an assembly of fine metal lines as explained later or a strip-shapedmetal film and the like.

In the non-display area NDA, a strip-shaped area disposed on the rightside of the second substrate SUB2 to elongate in the second direction Yis referred to as a first area A1, a strip-shaped area disposed on theleft side of the second substrate SUB2 to elongate in the seconddirection Y is referred to as a second area A2, a strip-shaped areadisposed on the lower side of the second substrate SUB2 to elongate inthe first direction X is referred to as a third area A3, and astrip-shaped area disposed on the upper side of the second substrateSUB2 to elongate in the first direction X is referred to as a fourtharea A4.

The expanded portions RSL arranged in the second direction Y form anexpanded portion group SR which will be described later in detail. Inthe example illustrated, the expanded portions RSL are arranged on rightand left end portions of the display area DA elongating in the firstarea A1 and the second area A2. The illustration is simplified, but agap between the adjacent expanded portions RSL is small and each of theexpanded portions RSL is configured to suppress leakage of the electricfield which will be explained later.

The display panel PNL includes lead lines L besides the common electrodeCE and the detection electrodes Rx. The lead lines L are disposed in thenon-display area NDA and located in the same plane as the detectionelectrodes Rx, on the second substrate SUB2. The lead lines L areelectrically connected to the expanded portions RSL of the detectionelectrodes Rx in a one-to-one correspondence. The lead lines L outputsensor output values from the detection electrodes Rx, respectively.

In the example illustrated, the lead lines L are disposed in the firstarea A1, or the second area A2 and the third area A3, on the secondsubstrate SUB2. For example, amongst the detection electrodes Rxarranged in the second direction Y, the lead lines L connected to theodd-numbered detection electrodes Rx are disposed in the second area A2and the third area A3, and the lead lines L connected to theeven-numbered detection electrodes Rx are disposed in the first area A1.The above-described layout of the lead lines L corresponds to theuniform width in the first direction X of the first area A1 and thesecond area A2 and to the narrow frame of the liquid crystal displaydevice DSP.

It should be noted that the layout of the lead lines L is not limited tothe example illustrated. For example, a layout in which the lead lines Lconnected to the detection electrodes Rx in the upper part of thedisplay area DA are located in the first area A1, and the lead lines Lconnected to the detection electrodes Rx in the lower part of thedisplay area DA are located in the second area A2 and the third area A3,may be adopted.

The expanded portion group SR on the left side is opposed to a side edgeportion on the second area A2 side of the first electrode Ca1 at theleft end, in planar view. In the present embodiment, the side edge ofthe left-side expanded portion group SR which is on the second area A2side, and the side edge of the left-end first electrode Ca1 which is onthe second area A2 side extend along a boundary between the display areaDA and the non-display area NDA, and said side edge of the left-sideexpanded portion group SR is in line with said side edge of the left-endfirst electrode Ca1 in the third direction Z.

The right-side expanded portion group SR is constituted similarly to theleft-side expanded portion group SR.

Each of the first electrodes Ca is electrically connected to the commonelectrode driver CD. For example, at least a part of the commonelectrode driver CD is built in the driver IC chip IC1 but is notlimited to this example. For example, the common electrode driver CD maybe disposed outside the driver IC chip IC1. The common electrode driverCD functions as a driving module configured to supply a common drivesignal to the common electrode CE at the display drive of displaying theimages, and to supply a sensor drive signal to the common electrodes CEat the sensing drive for sensing.

The flexible printed circuit FPC2 is connected to the second substrateSUB2 and also electrically connected to each of the lead lines L, in thenon-display area NDA on the lower side (i.e., the side close to thedriver IC chip IC1) of the drawing. The detection circuit RC is builtin, for example, the driver IC chip IC2. The sensor drive signal fromthe common electrode CE is received as the detection signal by thedetection electrodes Rx, and the detection circuit RC reads as sensoroutput values the variation in the detection signals supplied from thedetection electrodes Rx via the lead lines L connected to the detectionelectrodes Rx. The detection circuit RC having such a function detectscontact or approach of a detected object to the liquid crystal displaydevice DSP, based on the sensor output values from the detectionelectrodes Rx. Furthermore, the detection circuit RC can also detectposition information about the portion which the detected objectcontacts or approaches. The detection circuit RC may be disposed in thecontrol module CM.

FIG. 6 is an enlarged plan view showing a part of the sensor SE shown inFIG. 5.

As shown in FIG. 6, the first electrodes Ca of the common electrode CEare arranged in the first direction X, in the display area DA. Each ofthe first electrodes Ca has a first width Wca in the first direction X.The first width Wca is a distance between long sides of the strip-shapedfirst electrodes Ca and is constant along a length direction of thefirst electrodes Ca. Desirably, however, the first width Wca is aninteger multiple of a pixel pitch Pu which extends in the firstdirection X of the pixel PX. The pixel pitch Pu is a pitch in the firstdirection X of the centers of source lines S shown in FIG. 4. The pixelpitch Pu is not particularly limited but, in the present embodiment, thepixel pitch Pu is in a range of 30 to 60 μm.

A first width Wca1 of the first electrodes Ca1 and Cak on the outermostedges, of the first widths Wca of the respective first electrodes Ca, issmaller than a first width Wca2 in the first direction X of each of theother first electrodes Ca (Ca2, Ca3, . . . Cak−1). In the presentembodiment, the first electrode Ca1 on the left edge and the firstelectrode Cak on the right edge have the same first width Wca1. Thefirst electrodes Ca (Ca2, Ca3, . . . Cak−1) at the positions other thanthe edges have the same first widths Wca2.

In the present specification, the same widths indicate that the widthsare completely the same. Furthermore, this also indicates that adifference in number of the pixels PX arranged in the first direction X,of the pixels PX using the first electrodes Ca, is smaller than or equalto three. Moreover, this also indicates that a difference in widths inthe first direction X of the first electrodes Ca is smaller than orequal to 180 μm.

In the present embodiments, the first widths Wca1 of the respectivefirst electrodes Ca1 and Cak on both the edges are completely the sameas each other. The first widths Wca2 of the respective first electrodesCa (Ca2, Ca3, . . . Cak−1) at the positions other than the edges arecompletely the same as each other.

In addition, each sensor drive electrode Tx of the present embodiment iscomposed of one first electrode Ca. For example, the first sensor driveelectrode Tx1 is composed of the first electrode Ca1 on the edge.

In the present embodiment, the first sensor drive electrode Tx1comprising the first electrode Ca1 on the edge and the h-th sensor driveelectrode Txh comprising the first electrode Cak on the edge, of thesensor drive electrodes Tx, have the same shape and the same size. Thesecond sensor drive electrode Tx2 to the h−1-th sensor drive electrodeTxh−1 not including the first electrodes Ca1 and Cak on the edges, ofthe sensor drive electrodes Tx, have a different shape and a differentsize from each of the first sensor drive electrode Tx1 and the h-thsensor drive electrode Txh. In addition, a drive width Wt of each of thefirst sensor drive electrode Tx1 and the h-th sensor drive electrode Txhis referred to as a first drive width Wt1 and a drive width Wt of eachof the second sensor drive electrode Tx2 to the h−1-th sensor driveelectrode Txh−1 is referred to as a second drive width Wt2.

In the present embodiment, the drive width Wt in the first direction Xof the sensor drive electrode Tx is the same as the first width Wca ofthe corresponding first electrode Ca. For example, the first drive widthWt1 is the same as the first width Wca1. In addition, the second drivewidth Wt2 is the same as the first width Wca2. The first drive width Wt1is smaller than the second drive width Wt2.

Side edges of the first electrodes Ca1 and Cak on the edges on thenon-display area NDA side, of the common electrode CE, are arranged atpositions overlaid on boundaries B between the display area DA and thenon-display area NDA, in the example illustrated. However, displacementin bonding of the first substrate SUB1 and the second substrate SUB2often occurs in the structure in which the common electrode CE isdisposed on the first substrate SUB1 and the light-shielding layer BM isdisposed on the second substrate SUB2 as explained above. For thisreason, the side edges of the first electrodes Ca1 and Cak are notnecessarily in line with the boundaries B, and may be displaced towardthe display area DA side or the non-display area NDA side from theboundaries B, by a distance corresponding to the displacement in bondingof the substrates.

Each detection electrode Rx comprises the expanded portion RSL and thebody portion RR connected to each other.

The expanded portion RSL is electrically connected to the lead line L.In addition, the expanded portion RSL is not overlaid on the non-displayarea NDA and is disposed in the display area DA, in planar view. Theexpanded portion RSL is overlaid on the first electrode Ca1 on the edgeor the first electrode Cak on the edge alone, of the first electrodesCa. In the example illustrated, the side edge of the expanded portionRSL on the non-display area NDA side is located in the boundary B. Theexpanded portion RSL is located in a longitudinally elongated areaextending in the second direction Y and has a first width Ws1 in thesecond direction Y.

The body portion RR is formed in a strip shape to have an end portionlinked to the expanded portion RSL and is disposed in the display areaDA. In the display area DA, the body portion RR is opposed to the commonelectrode CE. The body portion RR is located in a laterally elongatedarea extending in the first direction X. In the present embodiment, thebody portion RR includes two split portions (slimline) RR1 and RR2 witha slit interposed between the split portions. Each of the split portionsRR1 and RR2 is formed in a strip shape and extends in the firstdirection X.

The number of the split portions of the body portion RR is not limitedto two, but may be one or three or more. In addition, the shape and thesize of the body portion RR are not particularly limited but can bevariously changed. The split portion RR1 has a second width Wr1 in thesecond direction Y. The split portion RR2 has a second width Wr2 in thesecond direction Y. A body width Wr is a sum of the second width Wr1 andthe second width Wr2 (Wr=Wr1+Wr2). In the present embodiment, the bodywidth Wr is uniform over the entire display area DA. Each of the secondwidths Wr1 and Wr2 is uniform over the entire display area DA. The bodywidth Wr is smaller than the first width Ws1. In other words, theexpanded portion RSL is wider than the body portion RR.

In the example illustrated, the expanded portion RSL is connected to twosplit portions RR1 and RR2 arranged in the second direction Y. Inaddition, the expanded portion RSL is arranged with the body portion RRin the first direction X to project from both sides of the body portionRR in the second direction Y.

When several parts of the detection electrode Rx illustrated (i.e., thesingle split portion RR1 and the single expanded portion RSL) arenoticed, the detection electrode Rx is substantially shaped in theletter T. The detection electrodes Rx on the opposite side of thedisplay area DA (not shown) are formed in the same shape, and one of thedetection electrodes Rx is substantially shaped in the letter I.

In the present embodiment, the body portion RR and the expanded portionRSL of the detection electrodes Rx is composed of a connection line CPand detection line LB. The connection line CP and the detection line LBare metallic. The connection line CP and the detection line LB can adopta structure of depositing a metal and a transparent conductive coatingsuch as ITO or the like. The connection line CP connects the expandedportion RSL and the lead line L. All the detection lines LB are disposedin the display area DA. Group of the detection lines LB is connected anend side of the connection line CP and an end side of the otherconnection line CP, and substantially extends in the first direction X.In the example illustrated, each of the detection lines LB has a grating(mesh) shape. Each of segments forming the grating extends in adirection different from the first direction X and the second directionY. As the detection lines LB, a first detection line LB1 forming theexpanded portion RSL and a second detection line LB2 forming the splitportions RR1 and RR2 are formed integrally.

The shape of the detection lines LB is not limited to grating but can bevariously modified. For example, the detection electrode Rx may beformed of detection lines having a shape of a waveform (morespecifically, a triangular waveform). The shape of the expanded portionsRSL of the detection electrode Rx is not limited to the linear waveform,but can also be a circular waveform of a sine wave or the like. In otherwords, desirably, protruding portions and recess portions may be engagedat edge portions of the expanded portions RSL adjacent in the seconddirection Y, and their boundary may not be thereby formed in a straightline.

An interval between the adjacent detection lines LB is remarkably small,an electric field hardly leaks from a small space surrounded by thedetection lines (i.e., a small space shaped in a diamond, in the presentembodiment) and is caught by the detection lines LB. From thisviewpoint, the following explanations are based on an assumption thatthe body portions RR and the expanded portion RSL of the detectionelectrode Rx are in a strip shape which does not generate an electricfield (or leakage of electric field) penetrating these portions, at acentral portion and an edge portion.

The first width Ws1 of the expanded portion RSL corresponds to adistance of the first detection line LB1 in the second direction Y. Eachof the second width Wr1 and the second width Wr2 corresponds to adistance of the second detection line LB2 in the second direction Y. Inaddition, the region of the expanded portion RSL is not the only regionoverlaid on the first detection line LB1, but corresponds to the regionsurrounded by a two-dot-chained line in the figure, and the firstdetection line LB1 extends to the two-dot-chained line. The regions ofthe split portions RR1 and RR2 are not the only regions overlaid on thesecond detection line LB2, but correspond to the regions surrounded bytwo-dot-chained lines in the figure, and the second detection line LB2extends to the two-dot-chained lines.

In the display area DA, dummy electrodes DR are disposed between theadjacent split portions RR1 and RR2, and between the adjacent bodyportions RR. Each of the dummy electrodes DR is formed of segmentscorresponding to the detection lines LB. For example, the segments ofthe dummy electrode DR are arranged in a grating shape and spaced apart.The dummy electrode DR is not connected to the lines such as the leadlines L or the detection lines LB, and is in an electrically floatingstatus. In the example illustrated, the dummy electrodes DR are disposedbetween the adjacent body portions RR and between the split portions RR1and RR2, and are not disposed between the adjacent expanded portionsRSL.

The detection electrodes Rx are arranged in the second direction Y. Theexpanded portions RSL of the detection electrodes Rx arranged in thesecond direction Y are disposed to be adjacent to each other. In otherwords, in each detection electrode Rx, the segments of the detectionlines LB constituting the expanded portion RSL are arranged atsubstantially regular intervals. The dummy electrode DR is notinterposed between one of the expanded portions and the other expandedportion. The segments of the respective detection lines LB are arrangedin the second direction Y at substantially regular intervals. Theleakage of the electric field from the region between the expandedportions RSL is suppressed by disposing the detection lines LB asexplained above.

The expanded portions RSL constituting the expanded portion group SR arephysically separated from each other, but the detection lines LB aredisposed as explained above. For this reason, the expanded portion groupSR can exert an electric field blocking function of substantiallyblocking the electric field without gaps in the entire region along aboundary between the display area DA and the first area A1 and theentire region along a boundary between the display area DA and thesecond area A2. An electric line of force is not extracted from thedisplay area DA to the first area A1 and the second area A2 but iscaught by any one of the expanded portions RSL, and an electric field isformed between the expanded portion RSL and the common electrode CE.

In other words, the electrostatic capacitance is formed between thecommon electrode CE and the expanded portion RSL, through the gapbetween the body portions RR and the gap between the split portions RR1and RR2. As a result, formation of the capacitance between the commonelectrode CE and the lead lines L through the gaps can be suppressed.For example, since formation of the capacitance can be suppressedbetween portions located at gaps between the detection electrodes Rx ofthe common electrode CE and the lead lines L connected to detectionelectrodes different from the detection electrodes Rx, a detection errorof the sensor SE can be suppressed.

FIG. 7 is another enlarged plan view showing a part of the sensor SEshown in FIG. 5.

As shown in FIG. 7, an area in which the first sensor drive electrodeTx1 is opposed to the detection electrodes Rx in planar view is referredto as first area S1. An area in which the second sensor drive electrodeTx2 is opposed to the detection electrodes Rx in planar view is referredto as second area S2. It should be noted that an area in which the h-thsensor drive electrode Txh is opposed to the detection electrodes Rx inplanar view is also the first area S1 and that an area in which each ofthe third sensor drive electrode Tx3 to the h−1-th sensor driveelectrode Txh−1 is opposed to the detection electrodes Rx in planar viewis also the second area S2.

In the present embodiment, the first area S1 is slightly larger than thesecond area S2. In the present embodiment, however, the body width Wr isuniform over the entire display area DA. In the sensor drive electrodeTx, the first drive width Wt1 is set to be smaller than the second drivewidth Wt2. The first area S1 can be made to close to the second area S2and the difference between the first area S1 and the second area S2 canbe reduced as compared with an assumption that the first drive width Wt1is equal to the second drive width Wt2. The first area S1 can be made tobe equal to the second area S2 by making the first drive width Wt1further smaller, unlike the present embodiment. In this case, thedifference between the first area S1 and the second area S2 becomeszero.

FIG. 8 is a line graph representing a value of capacitance Cc betweenthe sensor drive electrodes Tx and the detection electrodes Rx, in eachsensor drive electrode Tx.

As shown in FIG. 8, the value of capacitance Cc between the sensor driveelectrode Tx and the detection electrodes Rx is proportional to the areain which the sensor drive electrode Tx is overlapped to the detectionelectrodes Rx. The value of the capacitance Cc between each of thesecond sensor drive electrode Tx2 to the h−1-th sensor drive electrodeTxh−1 and the detection electrodes Rx is uniform, i.e., Vc2. Incontrast, the value of the capacitance Cc between each of the firstsensor drive electrode Tx1 and the h-th sensor drive electrode Txh, andthe detection electrodes Rx is uniform, i.e., Vc1 greater than thecapacitance value Vc2. In the present embodiment, however, since theabsolute value of the difference between the first area S1 and thesecond area S2 is reduced as explained above, capacitance difference ΔVc1 which is the absolute value of the difference between thecapacitance value Vc2 and the capacitance value Vc1 is also reduced.

When a finger or the like contacts or approaches the input surface ofthe liquid crystal display device DSP, variation in the capacitancegenerated at the detection electrodes Rx can hardly be made relativelysmall by suppressing the irregularity of the capacitance Cc as explainedabove.

With reference to the above matters, in the present embodiment,irregularity of the capacitance Cc on the entire regions of the sensorSE is suppressed by physical means of making the widths of the drivingelectrodes Tx for the first electrodes Ca on the edges different fromthose for the first electrodes Ca at positions other than the edges. Asa result, the sensor SE capable of exactly detecting input positioninformation is formed.

FIG. 9 is a cross-sectional view showing a structure of the displaypanel PNL including several parts of the sensor SE. The main portionsalone necessary for explanations are shown in the figure.

As shown in FIG. 9, a frame-shaped sealing member SEA is disposed in aregion which becomes the non-display area NDA in planar view, betweenthe first substrate SUB1 and the second substrate SUB2. The liquidcrystal layer LC is sealed in a space surrounded by the first substrateSUB1, the second substrate SUB2 and the sealing member SEA. The commonelectrode CE and the pixel electrodes PE are located on an inner surfaceside of the first substrate SUB1 which is opposed to the secondsubstrate SUB2. The common electrode CE is located on the secondinsulating film 12 and covered with the third insulating film 13. Thepixel electrodes PE are located on the third insulating film 13 and areopposed to the common electrode CE. The number of the pixel electrodesPE located just above the common electrode CE is not limited to this.Illustration of various lines such as a source line and the firstalignment film are omitted.

The light-shielding layer BM, the color filters CFR, CFG and CFB, theovercoat layer OC, and a peripheral light-shielding layer LS are locatedon an inner surface side of the second substrate SUB2 which is opposedto the first substrate SUB1. In the display area DA, the color filtersCFR, CFG and CFB are opposed to each pixel electrode PE. Thelight-shielding layer BM is located at each of boundaries of the colorfilters CFR, CFG and CFB. In the non-display area NDA, the peripherallight-shielding layer LS is located on the inner surface of the secondinsulating substrate 20. The peripheral light-shielding layer LS can beformed of the same material as the light-shielding layer BM. Theovercoat layer OC extends over the display area DA and the non-displayarea NDA. Illustration of the second alignment film is omitted.

The detection electrodes Rx and the lead lines L are located on theouter surface side of the second substrate SUB2, which is opposite tothe side opposed to the first substrate SUB1. The detection electrodesRx and the lead lines L can be formed of the same material, for example,a metallic material such as aluminum (A1), titanium (Ti), silver (Ag),molybdenum (Mo), tungsten (W), copper (Cu) or chromium (Cr) or an alloyusing the metallic materials. Each of the detection electrodes Rx andthe lead lines L may be a single-layer body of the metallic material ora laminate body formed by stacking layers of the metallic materials.Furthermore, each of the detection electrodes Rx and the lead lines Lmay be formed of an assembly of a single-layer body or laminate body ofthe metallic material and a transparent conductive coating of ITO or thelike.

A sealing member SEA is disposed under the lead lines L. The detectionelectrode Rx located in the display area DA is formed of theuntransparent metallic material but does not remarkably reduce thetransmittance of each pixel since the detection electrode Rx is composedof, for example, the detection lines LB formed of wires having a widthof approximately 3 to 5 μm. In addition, since each of the detectionlines LB is formed of a wire extending in a direction different from thedirections of alignment of the pixels (i.e., the first direction X andthe second direction Y) as shown in FIG. 6, moire of the pixel layout issuppressed and the deterioration in display quality is also suppressed.

A protective film PT is further disposed on the outer surface side ofthe second substrate SUB2. The protective film PT covers the detectionelectrode Rx and the lead lines L. The protective film PT is formed of,for example, a transparent resin material or a transparent inorganicmaterial.

Next, operations of a display period of displaying an image at theliquid crystal display device DSP having the above-explainedconfiguration will be explained.

First, an off status in which no fringe field is formed in the liquidcrystal layer LC will be explained. The off status is a status in whicha potential difference is not formed between the pixel electrode PE andthe common electrode CE. In the off status, liquid crystal moleculescontained in the liquid crystal layer LC are subjected to initialalignment in one orientation in the X-Y plane by the alignmentrestriction force between the first alignment film AL1 and the secondalignment film AL2.

The light from the backlight unit BL is partially transmitted throughthe polarizer of the first optical element OD1 and is made incident onthe display panel PNL. The light made incident on the display panel PNLis the linearly polarized light which is orthogonal to an absorptionaxis of the polarizer. The polarized status of the linearly polarizedlight hardly changes when the linearly polarized light passes though thedisplay panel PNL in the off status. For this reason, most of thelinearly polarized light which has passed through the display panel PNLis absorbed by the polarizer of the second optical element OD2 (blackdisplay). In other words, the light from the backlight unit BL does notcontribute to the display, and a black screen is displayed in thedisplay area DA. A mode of displaying the black screen on the displaypanel PNL in the off status is called a normally black mode.

Next, the on status in which the fringe field is formed in the liquidcrystal layer LC will be explained. The on-status corresponds to astatus in which a potential difference is formed between the pixelelectrode PE and the common electrode CE. In the on status, the commondrive signal is supplied from the common electrode driver CD to thecommon electrodes CE. On the other hand, a video signal to form thepotential difference for the common potential is supplied to the pixelelectrode PE. The fringe field is thereby formed between the pixelelectrodes PE and the common electrodes CE.

In the on-status, the liquid crystal molecules are aligned in anorientation different from an orientation of the initial alignmentwithin X-Y plane due to the fringe field formed within the liquidcrystal layer LC. The linearly polarized light orthogonal to theabsorption axis of the polarizer of the first optical element OD1 ismade incident on the display panel PNL and the polarized status isvaried in response to the alignment status of the liquid crystalmolecules when passing through the liquid crystal layer LC. For thisreason, at least part of the light which has passed through the liquidcrystal layer LC is transmitted through the polarizer of the secondoptical element OD2, in the on status (white display). In theabove-explained display modes, vicinity to the edges of the pixelelectrodes PE mainly contributes to the display since the fringe fieldis formed along the edges of the pixel electrodes PE.

Next, an operation in a sensing period for detecting the contact orapproach of an object in the liquid crystal display device DSP will beexplained.

The sensor drive signal is supplied from the common electrode driver CDto the sensor drive electrode Tx. Sensing is performed in such asituation. A principle in an example of a sensing method will beexplained with reference to FIG. 10.

As shown in FIG. 10, the capacitance Cc exists between the sensor driveelectrodes Tx and the detection electrodes Rx. Pulse-like write signals(sensor drive signals) Vw are sequentially supplied to the sensor driveelectrodes Tx in a predetermined cycle. In this example, a finger of auser is assumed to be close to a position at which a specific detectionelectrode Rx and a specific sensor drive electrode Tx intersect. Acapacitance Cx is generated by the detected object close to thedetection electrode Rx. When the pulse-like write signal Vw is suppliedto the sensor drive electrode Tx, a pulse-like read signal (sensoroutput value) Vr lower in level than pulses obtained from the otherdetection electrodes can be obtained from the specific detectionelectrode Rx.

The detection circuit RC shown in FIG. 5 can detect two-dimensionalposition information of the detected object in the X-Y plane of thesensor SE, based on the timing of supplying the write signal Vw to thesensor drive electrode Tx and the read signal Vr from each detectionelectrode Rx. In addition, the capacitance Cx obtained when the detectedobject is close to the detection electrode Rx is different from thatobtained when the detected object is remote from the detection electrodeRx. For this reason, the level of the read signal Vr obtained when thedetected object is close to the detection electrode Rx is different fromthat obtained when the detected object is remote from the detectionelectrode Rx. Therefore, the detection circuit RC can also detect theproximity of the detected object to the sensor SE (i.e., a distance in athird direction Z from the sensor SE), based on the level of the readsignal Vr.

The sensor-equipped liquid crystal display device DSP of the firstembodiment configured as explained above comprises the first electrodesCa, the display panel PNL including the detection electrodes Rx and thelead lines L, and the controller. The first electrodes Ca are disposedin the display area DA and arranged in the first direction X to bespaced apart by gaps, and each of the first electrodes Ca extends in thesecond direction Y. Each of the detection electrodes Rx comprises thebody portion RR and the expanded portion RSL. The body portion RR isopposed to the first electrodes Ca. The expanded portion RSL is opposedto the first electrode Ca1 (or the first electrode Cak) on the edge, ofthe first electrodes Ca, connected to the body portion RR, and is widerthan the body portion RR. The lead lines L are disposed in thenon-display area NDA and are electrically connected to the expandedportions RSL.

Each of the first electrodes Ca constitutes one corresponding sensordrive electrode Tx. The first drive width Wt1 of each of the firstsensor drive electrode Tx1 and the h-th sensor drive electrode Txh, ofthe sensor drive electrodes Tx, is smaller than the second drive widthWt2 of each of the second sensor drive electrode Tx2 to the h−1-thsensor drive electrode Txh−1. For this reason, even when the sensor SEuses the expanded portions RSL to suppress leakage of the electricfield, variation in the capacitance Cc over the entire regions of thesensor SE can be suppressed while reducing the area of the frame region.

In the present embodiment, the body width Wr of the body portion RR inthe second direction Y is uniform over the entire display area DA. Thesecond drive width Wt2 of each of the second sensor drive electrode Tx2to the h−1-th sensor drive electrode Txh−1 is uniform. For this reason,the second area S2 in which each of the second sensor drive electrodeTx2 to the h−1-th sensor drive electrode Txh−1 is opposed to thedetection electrodes Rx is uniform. For this reason, variation in thecapacitance Cc can be further suppressed.

With reference to the above matters, the sensor-equipped liquid crystaldisplay device DSP capable of accurately detecting input positioninformation can be obtained.

Comparative Example of First Embodiment

Next, the sensor-equipped liquid crystal display device DSP of acomparative example of the first embodiment will be explained. FIG. 11is an enlarged plan view showing a part of the sensor SE of thesensor-equipped liquid crystal display device of the comparativeexample.

As shown in FIG. 11, the present comparative example is different fromthe first embodiment with respect to features that the first width Wcais the same on the first electrodes Ca on the edges and the firstelectrodes Ca at positions other than the edges, and that the number ofthe first electrodes Ca and driving electrodes Tx is an odd number. Thedrive width Wt of each of odd-numbered sensor drive electrodes Tx, ofthe sensor drive electrodes Tx, is uniform and the same as the seconddrive width Wt2 of the first embodiment. For this reason, the area inwhich each of the sensor drive electrodes Tx at positions other than theedges, of the odd-numbered sensor drive electrodes Tx, is opposed to thedetection electrodes Rx, is uniform and the same as the second area S2of the first embodiment. It should be noted that the sensor SE of thepresent comparative example is not configured to make the area in whicheach of the sensor drive electrodes Tx on the edges is opposed to thedetection electrodes Rx, closer to the area in which each of the sensordrive electrodes Tx at positions other than the edges is opposed to thedetection electrodes Rx.

In addition, the drive width Wt of each of even-numbered sensor driveelectrodes Tx, of the sensor drive electrodes Tx, is uniform and smallerthan the drive width Wt of each of the odd-numbered sensor driveelectrodes Tx. In the present comparative example, the drive width Wt ofeach of the even-numbered sensor drive electrodes Tx is shorter than thedrive width Wt of each of the odd-numbered sensor drive electrodes Tx byone pixel or 30 to 60 μm. For this reason, the sensor SE of the presentcomparative example is not configured to make the area in which each ofthe odd-number sensor drive electrodes Tx at positions other than theedges is opposed to the detection electrodes Rx and the area in whicheach of the even-numbered sensor drive electrodes Tx is opposed to thedetection electrodes Rx uniform.

FIG. 12 is a line graph representing a value of capacitance Cc betweenthe sensor drive electrode Tx and the detection electrodes Rx, in eachsensor drive electrode Tx of the comparative example.

As shown in FIG. 12, the value of the capacitance Cc between each of theodd-numbered the sensor drive electrodes Tx at positions other than theedges and the detection electrodes Rx is a uniform value, i.e., Vc2. Incontrast, the value of the capacitance Cc between each of theeven-numbered sensor drive electrodes Tx and the detection electrodes Rxis uniform, i.e., Vc3 smaller than the capacitance value Vc2. For thisreason, capacitance difference ΔVc2, which is an absolute value of thedifference between the capacitance value Vc2 and the capacitance valueVc3, is consequently generated in the present comparative example.

The value of the capacitance Cc between each of the first sensor driveelectrode Tx1 and the h-th sensor drive electrode Txh on the edges andthe detection electrodes Rx is uniform, i.e., Vc4 greater than thecapacitance value Vc1 also shown in FIG. 8. For this reason, capacitancedifference ΔVc3, which is an absolute value of the difference betweenthe capacitance value Vc2 and the capacitance value Vc4, is consequentlygreater than the capacitance difference ΔVc1.

With reference to the above matters, variation in the capacitancegenerated at the detection electrodes Rx may be relatively small in thecomparative example. In other words, irregularity of the capacitance Ccon the entire regions of the sensor SE can hardly be suppressed andprocessing of accurately detecting the input position information isfurther required, and these elements are disadvantageous from theviewpoint of the detection time and the power consumption.

Second Embodiment

Next, a sensor-equipped liquid crystal display device DSP of a secondembodiment will be explained in detail. FIG. 13 is an enlarged plan viewshowing several parts of a sensor SE of the sensor-equipped liquidcrystal display device DSP of the present embodiment.

As shown in FIG. 13, the present embodiment is different from the firstembodiment with respect to features that a first width Wca is uniform infirst electrodes Ca on the edges and first electrodes at positions otherthan the edges, that the number of the first electrodes Ca is an oddnumber, that expanded portions RSL are also disposed in a non-displayarea NDA, and that each of sensor drive electrodes Tx is formed on thefirst electrodes Ca.

The first width Wca of each of the odd-numbered first electrodes Ca, ofthe first electrodes Ca, is uniform. In addition, the first width Wca ofeach of even-numbered first electrodes Ca, of the first electrodes Ca,is uniform and smaller than the first width Wca of each of theodd-numbered first electrodes Ca. In the present embodiment, the firstwidth Wca of each of the even-numbered first electrodes Ca is shorterthan the first width Wca of each of the odd-numbered first electrodes Caby one pixel or 30 to 60 μm.

The expanded portions RSL are disposed on the display area DA and thenon-display area NDA across boundaries B. The left expanded portion RSLof each of the detection electrodes Rx is opposed to a second region A2and a first electrode Ca1 on the edge. The right expanded portion RSL ofeach of the detection electrodes Rx is opposed to a first region A1 anda first electrode Cak on the edge. In the present embodiment, too, areaof a frame region can be reduced while suppressing leakage of anelectric field since at least several parts of the expanded portions RSLare disposed in the display area DA.

A relationship between the first electrodes Ca and the sensor driveelectrodes Tx in the present embodiment will be explained with referenceto FIG. 14. In the table, symbol ◯ represents the first electrode Caforming each of the sensor drive electrodes Tx.

As shown in FIG. 14, the first electrodes Ca are bundled and driven.Adjacent first electrodes Ca are simultaneously supplied with sensordrive signals from a controller, and the first electrodes Ca constitutethe sensor drive electrode Tx obtained by bundling the adjacent firstelectrodes. A first sensor drive electrode Tx1 and an h-th sensor driveelectrode Txh are the sensor drive electrodes on the edges, and each ofthem is composed of i first electrodes Ca. In this case, i represents anatural number. For this reason, the first sensor drive electrode Tx1 isformed of two or more first electrodes Ca which include the firstelectrode Ca1 and which are adjacent in the first direction X.Similarly, the h-th sensor drive electrode Txh is formed of two or morefirst electrodes Ca which include the first electrode Cak and which areadjacent in the first direction X. In the present embodiment, irepresents 2 (i=2).

Each of the second sensor drive electrode Tx2 to the h−1-th sensor driveelectrode Txh−1 is a sensor drive electrode at a position other than theedges and is formed of j first electrodes Ca adjacent to each other inthe first direction X. In this case, j represents a natural numbergreater than i. For this reason, each of the second sensor driveelectrode Tx2 to the h−1-th sensor drive electrode Txh−1 is formed oftwo or more first electrodes Ca adjacent to each other in the firstdirection X except the first electrodes Ca on the edges. In the presentembodiment, j represents 3 (j=3).

As shown in FIG. 13 and FIG. 14, a second sensor drive electrode Tx2 isformed at a position displaced from the first sensor drive electrode Tx1in the first direction X. The second sensor drive electrode Tx2 iscomposed of three adjacent first electrodes Ca. In the second sensordrive electrode Tx2, one or more first electrodes Ca forming the firstsensor drive electrode Tx1 are replaced. In addition, the second sensordrive electrode Tx2 comprises one or more first electrodes Ca formingthe first sensor drive electrode Tx1.

In the present embodiment, the second sensor drive electrode Tx2 isconfigured to comprise a first electrode Ca2 used for the first sensordrive electrode Tx1 and to comprise a first electrode Ca3 adjacent tothe first electrode Ca2 and a first electrode Ca4.

Each of a third sensor drive electrode Tx3 to the h−1-th sensor driveelectrode Txh−1 is also formed at a position displaced similarly fromone previous sensor drive electrode Tx in the first direction X. Forexample, the third sensor drive electrode Tx3 is composed of threeadjacent first electrodes Ca. In addition, in the third sensor driveelectrode Tx3, one or more first electrodes Ca constituting the secondsensor drive electrode Tx2 are replaced. In addition, the third sensordrive electrode Tx3 comprises one or more first electrodes Ca formingthe second sensor drive electrode Tx2.

In the present embodiment, the third sensor drive electrode Tx3 isconfigured to comprise the first electrode Ca4 used for the secondsensor drive electrode Tx2 and to comprise a first electrode Ca5adjacent to the first electrode Ca4 and a first electrode Ca6. For thisreason, with reference to the unit of the first electrodes Ca, each ofthe third sensor drive electrode Tx3 to the h−1-th sensor driveelectrode Txh−1 is constituted by bundling three first electrodes Ca anddisplaced in the first direction X by two first electrodes Ca.

Since each of the second sensor drive electrode Tx2 to the h−1-th sensordrive electrode Txh−1 is constituted by bundling three first electrodesCa as explained above with reference to FIG. 13, the second drive widthWt2 of these sensor drive electrodes is approximately the same. In thepresent embodiment, each of the second sensor drive electrode Tx2 to theh−1-th sensor drive electrode Txh−1 is constituted by two even-numberedfirst electrodes Ca and one odd-numbered first electrode Ca. For thisreason, the second drive width Wt2 of the present embodiment iscompletely the same. Since each of the first sensor drive electrode Tx1and the h-th sensor drive electrode Txh on the both edges is constitutedby bundling two first electrodes Ca, the first drive width Wt1 of thesesensor drive electrodes is smaller than the second drive width Wt2.

In the present embodiment, too, an area in which each of the firstsensor drive electrode Tx1 and the h-th sensor drive electrode Txh isopposed to the detection electrodes Rx is referred to as first area S1in planar view. An area in which each of the second sensor driveelectrode Tx2 to the h−1-th sensor drive electrode Txh−1 is opposed tothe detection electrodes Rx is referred to as second area S2.

As explained above, the second drive width Wt2 of each of the secondsensor drive electrode Tx2 to the h−1-th sensor drive electrode Txh−1 isuniform. In the present embodiment, too, the body width Wr of the bodyportion RR in the second direction Y is uniform over the entire displayarea DA. For this reason, the second area S2 in which each of the secondsensor drive electrode Tx2 to the h−1-th sensor drive electrode Txh−1 isopposed to the detection electrodes Rx is uniform.

In the present embodiment, the first area S1 is slightly larger than thesecond area S2. In the present embodiment, however, the first area S1can be made to close to the second area S2 and the difference betweenthe first area S1 and the second area S2 can be reduced as compared withan assumption that each of the first sensor drive electrode Tx1 and theh−th sensor drive electrode Txh is formed by bundling three firstelectrodes Ca. For this reason, the first area S1 can be made to beequal to the second area S2 and the difference between the first area S1and the second area S2 can be reduced to zero in accordance withconditions concerning the sensor SE.

In the present embodiment, irregularity of the capacitance Cc issuppressed by reducing the difference between the first area S1 and thesecond area S2. As a result, when a finger or the like contacts orapproaches the input surface of the liquid crystal display device DSP,variation in the capacitance generated at the detection electrodes Rxcan hardly be made relatively small.

With reference to the above matters, the magnitude of the widths of thesensor drive electrodes Tx on the both edges in the sensing period issubstantially changed by changing the number of the bundled firstelectrodes Ca and driving the sensing, in the present embodiment. Then,driving processing of reducing the difference between the first area S1and the second area S2 is performed. In the present embodiment, too,irregularity of the capacitance Cc on the entire regions of the sensorSE is thereby suppressed and the liquid crystal display device DSPcapable of accurately detecting the input position information isformed.

It should be noted that i and j can be variously modified and that i isnot limited to 2 and j is not limited to 3. In addition, the firstelectrodes Ca used by the sensor drive electrodes Tx may not beoverlapped, unlike the present embodiment. For this reason, the sensordrive electrodes Tx may be displayed in the first direction X.

Next, a method of driving the liquid crystal display device DSP of thepresent embodiment will be explained.

An example of performing sensing drive during successive display driveat plural times will be explained. It should be noted that one displaydrive indicates display drive in at least one horizontal scanningperiod, which drives at least pixels PX in a row arranged in the firstdirection X.

FIG. 15 is a timing chart for explanation of a method of driving theliquid crystal display device DSP of the present embodiment,illustrating a video signal Vsig, a common drive signal Vcom, and awrite signal Vw, in a first period of an F-th frame period.

As shown in FIG. 15, the F frame period which is the F-th frame periodis, for example, one sixtieth second. The F frame period is divided intotwo periods, i.e., a first period and a second period following thefirst period. Each of the first period and the second period is a halfof the frame period. In the present embodiment, reading the read signalVr from one detection electrode Rx is completed in the first period.Driving of the first period will be explained here.

In the first period, a controller (driver IC chip IC1, driver IC chipIC2, and control module CM) repeats display drive performed during eachof display periods Pd and sensing drive performed during sensing periodsPs other than the display period. The sensing periods Ps are, forexample, blanking periods Pb. In addition, in each sensing period Ps, awrite signal Vw can be written to one sensor drive electrode Tx and aread signal Vr can be read from the detection electrode Rx.

In each display period Pd, the source line driver SD outputs the videosignal Vsig to the source lines S and the common electrode driver CDsupplies the common drive signal Vcom to the common electrode (firstelectrodes Ca), under control of the driver IC chip IC1. The videosignal is thereby written to each of the pixels and the display isimplemented. In the display period Pd, the detection electrodes Rx areset in, for example, an electrically floating status.

As shown in FIG. 15 and FIG. 16, the driver IC chip IC1 drives the firstsensor drive electrode Tx1 in a first sensing period Ps of the firstperiod. More specifically, the common electrode driver CD writes writesignals (sensor drive signals) Vw to the first electrode Ca1 and thefirst electrode Ca2. The driver IC chip IC2 reads the read signals Vrfrom the detection electrodes Rx. In other words, the input positioninformation can be taken from the detection electrodes Rx. The readsignals Vr are signals indicating variation in sensor signals generatedbetween the first sensor drive electrode Tx1 and the detectionelectrodes Rx, based on the write signals Vw. In FIG. 16 or FIG. 17 toFIG. 19, hatch lines are drawn in regions in which the sensor driveelectrodes Tx to write the signals and the detection electrodes Rx toread the signals are opposed.

Then, as shown in FIG. 15 and FIG. 17, the driver IC chip IC1 drives thesecond sensor drive electrode Tx2 in a second sensing period Ps of thefirst period. More specifically, the common electrode driver CD writesthe write signals (sensor drive signals) Vw to the first electrode Ca2,the first electrode Ca3 and the first electrode Ca4. The driver IC chipIC2 reads the read signals Vr from the detection electrodes Rx. The readsignals Vr are signals indicating variation in sensor signals generatedbetween the second sensor drive electrode Tx2 and the detectionelectrodes Rx, based on the write signals Vw. The first electrode Ca2 iscommonly used in the first sensing period Ps and the second sensingperiod Ps.

Then, as shown in FIG. 15 and FIG. 18, the driver IC chip IC1 drives thethird sensor drive electrode Tx3 in a third sensing period Ps of thefirst period. More specifically, the common electrode driver CD writesthe write signals (sensor drive signals) Vw to the first electrode Ca4,the first electrode Ca5 and the first electrode Ca6. The driver IC chipIC2 reads the read signals Vr from the detection electrodes Rx. The readsignals Vr are signals indicating variation in sensor signals generatedbetween the third sensor drive electrode Tx3 and the detectionelectrodes Rx, based on the write signals Vw. The first electrode Ca4 iscommonly used in the second sensing period Ps and the third sensingperiod Ps.

After that, in the fourth sensing period Ps to the h−1-th sensing periodPs, of the first period, too, the write signals Vw are written and theread signals Vr are read similarly to the second and third sensingperiods Ps.

Then, as shown in FIG. 15 and FIG. 19, the driver IC chip IC1 drives theh-th sensor drive electrode Txh in an h−th sensing period Ps of thefirst period. More specifically, the common electrode driver CD writesthe write signals (sensor drive signals) Vw to the first electrode Cak−1and the first electrode Cak. The driver IC chip IC2 reads the readsignals Vr from the detection electrodes Rx. The read signals Vr aresignals indicating variation in sensor signals generated between theh-th sensor drive electrode Txh and the detection electrodes Rx.

As explained above, driving of the first period is performed. The inputposition information can be detected on the entire regions of thedisplay area DA by performing the sensing drive while replacing thedetection electrodes Rx to read the signals.

The display periods Pd and the sensing periods Ps are repeated in thepresent embodiment (FIG. 15) but setting of these periods is not limitedto the present embodiment and can be variously modified. For example,each of the display period and the sensing period may be combined to oneperiod in the first period.

The sensor-equipped liquid crystal display device DSP of the secondembodiment configured as explained above comprises the first electrodesCa, the display panel PNL including the detection electrodes Rx and thelead lines L, and the controller. Since each of the first sensor driveelectrode Tx1 and the h-th sensor drive electrode Txh is opposed to theexpanded portions RSL, the sensor drive electrode is formed by bundlingtwo first electrodes Ca. Since each of the second sensor drive electrodeTx2 to the h−1-th sensor drive electrode Txh−1 is not opposed to theexpanded portions RSL but to the split portions alone, the sensor driveelectrode is formed by bundling three first electrodes Ca.

The first drive width Wt1 of each of the first sensor drive electrodeTx1 and the h-th sensor drive electrode Txh, of the sensor driveelectrodes Tx, is smaller than the second drive width Wt2 of each of thesecond sensor drive electrode Tx2 to the h−1-th sensor drive electrodeTxh−1. For this reason, the same advantages as those of the firstembodiment can be obtained in the present embodiment.

With reference to the above matters, the sensor-equipped liquid crystaldisplay device DSP capable of accurately detecting input positioninformation can be obtained.

Third Embodiment

Next, a sensor-equipped liquid crystal display device DSP of a thirdembodiment will be explained. FIG. 20 is a plan view showing aconfiguration of a sensor SE of the sensor-equipped liquid crystaldisplay device DSP of the present embodiment. The main portions alonenecessary for explanations are shown in the figure.

As shown in FIG. 20, the present embodiment is different from the firstembodiment (FIG. 5) with respect to features that the number of firstelectrodes Ca and driving electrodes Tx is an odd number, that a commonelectrode CE comprises not only k first electrodes Ca1 to Cak, but alsotwo second electrodes Cb1 and Cb2, and that expanded portions RSL areopposed to the second electrodes Cb1 and Cb2.

The second electrode Cb1 is disposed at an edge portion of a displayarea DA and extends in the second direction Y. More specifically, thesecond electrode Cb1 is adjacent to the first electrode Ca1 on the edgelocated on the outermost side of the first electrodes Ca but is spacedapart from the electrode in the first direction X. The second electrodeCb2 is constituted similarly. For this reason, the electrodes on theedges are not the first electrodes Ca1 and Cak, but the secondelectrodes Cb1 and Cb2, in the common electrode CE.

In the present embodiments, first widths Wca2 of the respective firstelectrodes Ca2 to Cak−1 are second drive widths Wt2 and are the same aseach other. First widths Wca1 of the respective first electrodes Ca1 andCak are first drive widths Wt1 and are the same as each other, and eachof the width is smaller than the first width Wca2. Second widths Wcb ofthe respective second electrodes Cb1 and Cb2 in the first direction Xare the same as each other, and each of the width is smaller than thefirst width Wca1. In addition, the second width Wcb is smaller than awidth of the first direction X of the expanded portion RSL. The secondwidth Wcb is an interval between long sides of the strip-shaped secondelectrodes Cb and is constant along a length direction of the secondelectrodes Cb.

Body portions RR of the detection electrodes Rx are opposed to the firstelectrodes Ca1 to Cak but are not opposed to the second electrodes Cb1and Cb2. Expanded portions RSL of the detection electrodes Rx areopposed to at least the second electrodes Cb. In the present embodiment,the entire bodies of the expanded portions RSL are disposed in thedisplay area DA. The left expanded portion RSL is opposed to both thefirst electrode Ca1 and the second electrode Cb1. The right expandedportion RSL is opposed to both the first electrode Cak and the secondelectrode Cb2.

The sensor-equipped liquid crystal display device DSP of the presentembodiment is configured as explained above.

In the display period, the controller (driver IC chip IC1) supplies thesame common drive signal Vcom as the signal supplied to the firstelectrodes Ca1 to Cak to each of the second electrodes Cb1 and Cb2. Thecontroller (driver IC chip IC1) maintains an electric potential of eachof the second electrodes Cb1 and Cb2 at a value different from theelectric potentials of the sensor drive electrodes Tx, in the sensingperiod.

For example, the controller maintains the second electrode Cb at theground potential in the sensing period. Alternatively, the controllerchanges the second electrode Cb to an electrically floating status inthe sensing period. Alternatively, the controller supplies the commondrive signal Vcom to the second electrode Cb in the sensing period. Thecontroller may drive the second electrode Cb to be at a desiredpotential in the sensing period in a case other than the above.

With reference to the above matters, the second electrodes Cb are usedfor display drive and are not substantially used for sensing drive.

In the present embodiment, the first area S1 is made close to the secondarea S2 by a combination of physical means of making the first widthsWca of the first electrodes Ca1 and Cak on the edges different fromthose of the first electrodes Ca2 to Cak−1 at positions other than theedges with a driving method of not using the second electrodes Cb forthe sensor drive electrodes Tx. Irregularity of the capacitance Cc onthe entire regions of the sensor SE is thereby suppressed and the sensorSE capable of accurately detecting the input position information isformed.

The sensor-equipped liquid crystal display device DSP of the thirdembodiment configured as explained above comprises the first electrodesCa, two second electrodes Cb, the display panel PNL including thedetection electrodes Rx and the lead lines L, and the controller. Sinceeach of the first sensor drive electrode Tx1 and the h-th sensor driveelectrode Txh is opposed to the expanded portions RSL, the first drivewidth Wt1 of each of the first sensor drive electrode Tx1 and the h-thsensor drive electrode Txh is smaller than the second drive width Wt2 ofeach of the second sensor drive electrode Tx2 to the h−1-th sensor driveelectrode Txh−1. In addition, the sensor drive electrodes Tx are formedwithout using the second electrodes Cb. For this reason, the sameadvantages as those of the first embodiment can be obtained in thepresent embodiment.

In the sensing period, the second electrodes located between the sensordrive electrodes Tx and the lead lines L function as shieldingelectrodes. For this reason, a parasitic capacitance between the sensordrive electrodes Tx and the lead lines L can be reduced even in aconfiguration in which the sensor drive electrodes Tx and the lead linesL are disposed to be close to each other. An operation error of thesensor SE resulting from the capacitive coupling between the sensordrive electrodes Tx and the lead lines L can be therefore suppressed.The electric potentials of the second electrodes Cb in the sensingperiod are not limited to the above example if the parasitic capacitancebetween the sensor drive electrodes Tx and the lead lines L can bereduced.

In addition, the second electrodes Cb are disposed in the display areaDA and function similarly to the first electrodes Ca in the displayperiod. For this reason, in the present embodiment, a space fordisposing the second electrodes Cb does not need to be secured in thenon-display area NDA and the frame regions can be made narrower, ascompared with a case where the second electrodes Cb are disposed in thenon-display area NDA. Furthermore, the second electrodes Cb can bedisposed on the second insulating film 12 together with the firstelectrodes Ca. For this reason, the second electrodes Cb can be formedof the same material as the first electrodes Ca in the same process, anda specific process for forming the second electrodes Cb can beunnecessary.

With reference to the above matters, the sensor-equipped liquid crystaldisplay device DSP capable of accurately detecting input positioninformation can be obtained.

Fourth Embodiment

Next, a sensor-equipped liquid crystal display device DSP of a fourthembodiment will be explained. FIG. 21 is a plan view showing aconfiguration of a sensor SE of the sensor-equipped liquid crystaldisplay device DSP of the present embodiment. The main portions alonenecessary for explanations are shown in the figure.

As shown in FIG. 21, the present embodiment is different from the thirdembodiment (FIG. 20) with respect to features that expanded portions RSLare opposed to second electrodes Cb1 and Cb2 but are not opposed tofirst electrodes Ca, and that a first drive width Wt1 is the same as asecond drive width Wt2. A first area S1 is equal to a second area S2,and a difference between the first area S1 and the second area S2 iszero.

In addition, a second width Wcb is equal to a width of the firstdirection X of the expanded portion RSL. The first drive width Wt1 andthe second drive width Wt2 can easily be made the same as each other byusing the second electrodes Cb1 and Cb2 similarly to the presentembodiment.

FIG. 22 is a line graph representing a value of capacitance Cc betweensensor drive electrodes Tx and the detection electrodes Rx, in eachsensor drive electrode Tx.

As shown in FIG. 22, a value of a capacitance Cc between each of thefirst sensor drive electrode Tx1 to the h-th sensor drive electrode Txh,and the detection electrodes Rx is uniform. When a finger or the likecontacts or approaches the input surface of the liquid crystal displaydevice DSP, variation in the capacitance generated at the detectionelectrodes Rx can hardly be made relatively small by canceling theirregularity of the capacitance Cc as explained above.

With reference to the above-explained matters, the first area S1 is madeequal to the second area S2 by a combination of physical means forurging the expanded portions RSL to be opposed to the second electrodesCb1 and Cb2 alone and not to be opposed to the first electrodes Ca witha driving method of not using the second electrodes Cb for the sensordrive electrodes Tx, in the present embodiment. Irregularity of thecapacitance Cc on the entire regions of the sensor SE is therebyprevented and the sensor SE capable of accurately detecting the inputposition information is formed.

In the sensor-equipped liquid crystal display device DSP of the fourthembodiment configured as described above, too, the same advantages asthose obtained in the third embodiment can be obtained.

With reference to the above matters, the sensor-equipped liquid crystaldisplay device DSP capable of accurately detecting input positioninformation can be obtained.

Fifth Embodiment

Next, a sensor-equipped liquid crystal display device DSP of a fifthembodiment will be explained. FIG. 23 is an enlarged plan view showingseveral parts of the sensor SE of the sensor-equipped liquid crystaldisplay device DSP of the present embodiment.

As shown in FIG. 23, the present embodiment is different from the secondembodiment with respect to features that a common electrode CE comprisesnot only k first electrodes Ca1 to Cak, but also two second electrodesCb1 and Cb2 and that expanded portions RSL are opposed to the secondelectrodes Cb1 and Cb2.

The second electrode Cb1 is disposed at an edge portion of a displayarea DA to extend in the second direction Y, and is adjacent to andspaced apart from the first electrode Ca1 in the first direction X.Similarly to this, the second electrode Cb2 is disposed at an edgeportion of the display area DA to extend in the second direction Y, andis adjacent to and spaced apart from the first electrode Cak in thefirst direction X.

In the present embodiment, first widths Wca of the respective firstelectrodes Ca1 to Cak are the same as each other. Second widths Wcb ofthe respective second electrodes Cb1 and Cb2 are the same as each other,and each of the width is smaller than the first width Wca. In addition,the second width Wcb is smaller than a width of the first direction X ofthe expanded portion RSL.

The left expanded portion RSL of each of the detection electrodes Rx isopposed to a second region A2, the second electrode Cb1 and the firstelectrode Ca1. The right expanded portion RSL of each of the detectionelectrodes Rx is opposed to a first region A1, the second electrode Cb2and the first electrode Cak.

A relationship among the first electrodes Ca, the second electrode Cb,and the sensor drive electrodes Tx in the present embodiment will beexplained with reference to FIG. 24. In the table, symbol ◯ representsthe first electrode Ca forming each of the sensor drive electrodes Tx.

As shown in FIG. 24, each of the first sensor drive electrode Tx1 andthe h-th sensor drive electrode Txh is a sensor drive electrode on theedge and is formed of i first electrodes Ca. In the present embodiment,i represents 2. Each of the first sensor drive electrode Tx1 and theh-th sensor drive electrode Txh is formed of two first electrodes Caincluding the first electrode Ca on the edge.

Each of the second sensor drive electrode Tx2 to the h−1-th sensor driveelectrode Txh−1 is a sensor drive electrode at a position other than theedges, and is formed of j first electrodes Ca adjacent to each other inthe first direction X. In the present embodiment, j represents 3. Eachof the second sensor drive electrode Tx2 to the h−1-th sensor driveelectrode Txh−1 is formed of three first electrodes Ca adjacent to eachother in the first direction X except the first electrodes Ca on theedges. The second electrode Cb does not form the sensor drive electrodeTx.

As shown in FIG. 23 and FIG. 24, the second sensor drive electrode Tx2is formed at a position displaced from the first sensor drive electrodeTx1 in the first direction X.

In the present embodiment, the second sensor drive electrode Tx2 isconfigured to comprise a first electrode Ca2 used for the first sensordrive electrode Tx1 and to comprise a first electrode Ca3 adjacent tothe first electrode Ca2 and a first electrode Ca4.

Each of a third sensor drive electrode Tx3 to a h−1-th sensor driveelectrode Txh−1 is also formed at a position displaced similarly fromone previous sensor drive electrode Tx in the first direction X. Forexample, of three first electrodes Ca forming the third sensor driveelectrode Tx3, two electrodes are replaced and one electrode isoverlapped in three first electrodes Ca forming the second sensor driveelectrode Tx2. For this reason, with reference to the unit of the firstelectrodes Ca, each of the third sensor drive electrode Tx3 to theh−1-th sensor drive electrode Txh−1 is formed by bundling three firstelectrodes Ca and displaced in the first direction X by two firstelectrodes Ca.

Since each of the second sensor drive electrode Tx2 to the h−1-th sensordrive electrode Txh−1 is formed by bundling three first electrodes Ca asexplained above with reference to FIG. 23, the second drive width Wt2 ofthese sensor drive electrodes is the same. Since each of the firstsensor drive electrode Tx1 and the h-th sensor drive electrode Txh isformed by bundling two first electrodes Ca, the first drive width Wt1 ofthese sensor drive electrodes is smaller than the second drive widthWt2.

As explained above, all the second drive widths Wt2 are uniform. In thepresent embodiment, too, the body width Wr of the body portion RR in thesecond direction Y is uniform over the entire display area DA. For thisreason, the second area S2 in which each of the second sensor driveelectrode Tx2 to the h−1-th sensor drive electrode Txh−1 is opposed tothe detection electrodes Rx is uniform.

In the present embodiment, the first area S1 is slightly larger than thesecond area S2. In the present embodiment, however, the first area S1can be made to close to the second area S2 and the difference betweenthe first area S1 and the second area S2 can be reduced as compared withan assumption that each of the first sensor drive electrode Tx1 and theh−th sensor drive electrode Txh is formed by bundling three firstelectrodes Ca. For this reason, the first area S1 can be made to beequal to the second area S2 in accordance with conditions concerning thesensor SE.

With reference to the above matters, the liquid crystal display deviceDSP capable of suppressing irregularity of the capacitance Cc on theentire regions of the sensor SE and accurately detecting the inputposition information is formed by a combination of a driving method ofperforming sensing drive by changing the number of the bundled firstelectrodes Ca with another driving method of not using the secondelectrodes Cb for the sensor drive electrodes Tx, in the presentembodiment. In the present embodiment, too, i and j can be variouslymodified, and the first electrodes Ca used by the sensor driveelectrodes Tx may not be overlapped. The method of driving the liquidcrystal display device DSP of the second embodiment can be used as amethod of driving the liquid crystal display device DSP of the presentembodiment. However, the second electrodes Cb are added to the liquidcrystal display device DSP of the present embodiment. For this reason,the controller (driver IC chip IC1) supplies the same common drivesignal Vcom as the signal supplied to the first electrodes Ca1 to Cak toeach of the second electrodes Cb1 and Cb2 in the display period. Then,the controller (driver IC chip IC1) maintains an electric potential ofeach of the second electrodes Cb1 and Cb2 at a value different from theelectric potentials of the sensor drive electrodes Tx, in the sensingperiod. With reference to the above matters, the second electrodes Cbare used for display drive and are not substantially used for sensingdrive.

According to the sensor-equipped liquid crystal display device DSP ofthe fifth embodiment configured as described above, the liquid crystaldisplay device DSP broadly corresponds to a combination of the secondembodiment with the third embodiment. For this reason, the advantages ofboth the second embodiment and the third embodiment can be obtained inthe present embodiment.

With reference to the above matters, the sensor-equipped liquid crystaldisplay device DSP capable of accurately detecting input positioninformation can be obtained.

Modified Example 1 of Embodiments

Next, the sensor-equipped liquid crystal display device DSP of modifiedexample 1 of the embodiments will be explained. Modified example 1 isdifferent from the above-described embodiments with respect to a featurethat each of first electrodes Ca of a common electrode CE extends in thefirst direction X and detection electrodes Rx substantially extend inthe second direction Y. The sensor-equipped liquid crystal displaydevice DSP of modified example 1 of the first embodiment will behereinafter explained.

As shown in FIG. 25, the common electrode CE includes first electrodesCa which are arranged in the second direction Y to be spaced apart fromeach other and which extend substantially linearly in the firstdirection X, in the display area DA. The detection electrodes Rx arearranged in first direction X to be spaced apart from each other andextend substantially linearly in the second direction Y, in the displayarea DA. The common electrode CE and the detection electrodes Rx areopposed to each other while sandwiching various dielectrics as describedabove. Each of the first electrodes Ca is electrically connected to acommon electrode driver CD. The lead lines L are disposed in thenon-display area NDA and are electrically connected to the detectionelectrodes Rx in a one-to-one relationship. The lead lines L aredisposed on, for example, the second substrate SUB2 similarly to thedetection electrodes Rx. Each of the lead lines L is electricallyconnected to the detection circuit RC via the flexible printed circuitFPC2. In the example illustrated, the lead lines L are disposed in thethird area A3 of the second substrate SUB2 on which the flexible printedcircuit FPC2 is mounted.

Each detection electrode Rx comprises a body portion RR located in thedisplay area DA, and an expanded portion RSL connected to the bodyportion RR and located at least partially in the display area DA, thoughnot described here. In the example illustrated, the expanded portionsRSL are located on the third area A3 side from the body portions RR, andthe entire regions of the expanded portions RSL are located in thedisplay area DA. The expanded portions RSL of the respective detectionelectrodes Rx are arranged in the first direction X to constitute anexpanded portion group SR. As explained above, the adjacent expandedportions RSL are configured to suppress leakage of the electric field,though illustrated simply.

In modified example 1, too, the same advantage as that obtained in theabove examples can be obtained. In addition, the length of the leadlines L making connection between the detection electrodes Rx and theflexible printed circuit FPC2 can be reduced and the noise of the leadlines L can be further reduced, as compared with the examples shown inFIG. 5 and the like.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

For example, the number, size, and shape and the like of the firstelectrodes Ca are not limited specifically and can be variously changed.

The driver IC chip IC1 and the driver IC chip IC2 may be formedintegrally. In other words, the driver IC chip IC1 and the driver ICchip IC2 can be integrated in a single driver IC chip. In this case, thesingle driver IC chip may be capable of driving the display panel PNLand the sensor SE, and detecting the position information from thesensor SE.

The above-explained controller is not limited to the driver IC chips IC1and IC2 and the control module CM but can be variously modified, may bea unit capable of electrically controlling the display panel PNL and thesensor SE.

The sensor-equipped display device in which the common electrode CEbuilt in the display panel PNL functions as the sensor drive electrodeand which comprises the detection electrodes Rx opposed to the sensordrive electrode and the lead lines L electrically connected to thedetection electrodes Rx, has been explained in the above embodiments,but the embodiments can also be applied to a sensor device which can becombined with a display panel including no sensor elements such as thesensor drive electrode and the detection electrodes by sticking or theother manner, as shown in FIG. 26. More specifically, the sensor deviceis configured to comprise a sensor panel including a sensor driveelectrode, detection electrodes and lead lines, and a controller.

The sensor drive electrode is disposed at a position opposed to thedisplay area of the display device. The detection electrodes are opposedto the sensor drive electrode. The lead lines are disposed at positionsopposed to the non-display area of the display device and electricallyconnected with the detection electrodes to allow the sensor output valueto be output from the detection electrodes. The driving module suppliesthe sensor drive signal to the sensor drive electrode and allows thesensor drive signal from the sensor drive electrode to be detected asthe detection signal by the detection electrodes to read the variationin the detection signal. In such a sensor device, each of the detectionelectrodes comprises the body portion and the expanded portion widerthan the body portion. The body portion is opposed to the sensor driveelectrode. At least a part of the expanded portion is opposed to thedisplay area and also opposed to the sensor drive electrode. In thissensor device, too, the same advantages as those of the above-explainedembodiments can be obtained.

What is claimed is:
 1. A sensor-equipped display device comprising: adisplay area; and a detection electrode provided in the display area,wherein the detection electrode comprises a body portion extending in afirst direction, and an expanded portion connected to the body portion,and being wider than the body portion in a second direction intersectingthe first direction, the detection electrode has a grating shape thathas a plurality of segments comprising metal lines extending in adirection different from the first direction and the second direction,each segment has an end portion that defines an outer edge of thedetection electrode, a first crossing portion which the segment andanother segment intersect and which is nearest to the end portion, and asecond crossing portion which the segment and another segment intersectand which is next to the first crossing portion, and a first distancebetween the end portion and the first crossing portion is smaller than asecond distance between the first crossing portion and the secondcrossing portion.
 2. The sensor-equipped display device of claim 1,wherein the first distance is smaller than half the second distance. 3.The sensor-equipped display device of claim 1, wherein one of the firstdistances are smaller than another first distance.
 4. Thesensor-equipped display device of claim 1, wherein the end portions ofthe body portion are lined in the first direction.
 5. Thesensor-equipped display device of claim 1, wherein each of the segmentsof the expanded portion has outermost crossing portions, and theoutermost crossing portions are lined in the second portion.
 6. Thesensor-equipped display device of claim 5, wherein the detectionelectrode further comprises a connection line extending in the seconddirection, and the outermost crossing portions are connected by theconnection line.
 7. The sensor-equipped display device of claim 5,wherein the display area is defined by side lines, and the outermostcrossing portions are located above one of the side lines.
 8. Thesensor-equipped display device of claim 7, wherein the detectionelectrode further comprises a connection line located above the one ofthe side lines, the outermost crossing portions are connected by theconnection line.
 9. The sensor-equipped display device of claim 1,further comprising: a plurality of dummy electrodes provided in thedisplay area, wherein each dummy electrode is provided in line with acorresponding one of the segments.
 10. The sensor-equipped displaydevice of claim 9, wherein the dummy electrodes comprise a plurality ofdummy segments which are formed of metal lines and which extend parallelto the segments of the detection electrode.
 11. The sensor-equippeddisplay device of claim 10, wherein each of the dummy segments has nocrossing portion crossing another dummy segment.
 12. The sensor-equippeddisplay device of claim 10, wherein the dummy electrodes have aplurality of outermost dummy segments, and each of the outermost dummysegments has an end portion facing the end portion of the segment of thedetection electrode with a gap.
 13. The sensor-equipped display deviceof claim 12, wherein a gap between the end portion of the segment of thedetection electrode and the end portion of the outermost dummy segmentof the dummy electrode is smaller than the first distance.
 14. Thesensor-equipped display device of claim 12, wherein a gap between theend portion of the segment of the detection electrode and the endportion of the outermost dummy segment of the dummy electrode is smallerthan half the first distance.
 15. The sensor-equipped display device ofclaim 12, wherein the dummy electrode has a first dummy segment and asecond dummy segment, one of the segments of the detection electrode,the first dummy segment and the second dummy segment are provided inline in this order, a first gap between the segment of the detectionelectrode and the first dummy segment is equal to a second gap betweenthe first dummy segment and the second dummy segment.
 16. Thesensor-equipped display device of claim 15, wherein the first dummysegment and the second dummy segment have the same length.